Automatic timing governor for internal combustion engines



Nov. 10, 1936. LA CHAPELLE 2,060,580

AUTOMATIC TIMING GOVERNOR FOR INTERNAL COMBUSTION ENGINES Filed 001;.1]., 1955 2 Sheets-Sheet 1 HIIHI HHIMH H H" llW- INVENTOR.

Nov. 10, 1936. E. LA CHAPELLE AUTOMATIC TIMING GOVERNOR FOR INTERNALCOMBUSTION ENGINES v Filed Oct. 11, 1955 2 Sheets-Sheet 2 INVENTOR. 12mm//(/4/1f ATTORNEY.

Patented Nov. 1 1936.

UNITED STATES PATENT OFF-ICE AUTOMATIC TIMING GOVERNOR FOB INTEBN 'ALCOMBUSTION ENGINES It is well known in the art of internal combustions,that as the engine speed increases it is necessary in order to obtaincomplete efficiency, to

accelerate the opening of the intake valves, in order to allowsuflicient time interval for the spark and the incoming gas to reach thecombustion chambers. This invention relates to adevice for automaticallyadvancing the intake valves and the ignition timing in accordance withand in proportion to the engine speed.

The principal object of. the invention is to provide a compact, simple,and highly efficient device which will automatically advance the timingof any desired valve or sets of valves in the engine this invention isto so construct the device that it can be employed to advance certain of'the valves, as for instance the intake valves, without disturbing thetiming of the exhaust valves, or 80 which can be employed to advance theintake and retard the exhaust simultaneously, as desired.

Other objects and advantages reside in the detail construction of. theinvention, which is designed for simplicity, economy, and emciency. 85These will become more apparent from the following description.

In the following detailed description of the in- I vention reference ishad to the accompanying drawings which form a part hereof. Like nu- 40merals refer to like parts in all views of the drawings and throughoutthe description.

In the drawings:--

Fig. 1 is a sectional view of one extremity of a typical engine camshaft housing and crank case,

45 illustrating the invention embodied therein.

Fig. 2 is a cross section illustrating a face view of the governorportion of the invention. This view is taken on the line 2-2, Fig. 1,illustrating the device in the at res position.

50 Fig. 3 is a similar face view of the complete device taken on theline 3-4, Fig. 1, illustrating the device in the high speed position.

Fig. 4 is a. longitudinal section, taken on the line 44, Fig. 2.

Fig. 5 is a detail view illustrating the cams of place the twist" in theintake cams.

atypical valve cam shaft constructed in accordance with this invention.

Fi 6 is a cross section through the cam shaft, of Fig. 5. v

In the drawings: the adjacent portions of an 5 engine crank case areindicated at ill with the crank shaft at H and the gear case cover atl2. A typical cam shaft drive gear is illustrated at l3 on the crankshaft for driving a valve cam shaft l4. A typical valve tappet or camfollower is in- 10 dicated at l8 with its guide at'l9.

The invention is designed to shift the cam shaft l4 longitudinally inaccordance with the speed of the engine. The cam shaft carries the usualnumber pf valve cams for opening and closing the intake andexhaust'valves of the engine. In using this invention, these cams areelongated axially. In Fig. 5, a typical exhaust valve cam is indicatedat l5, and a typical intake valve cam is indicated at [6. Either or bothof these cams may be milled 6 on a twist, such as shown at H, so thatthe higher portion of the cam will occur at a different radial positionat one end of the cam than at the other. It has been found that it isonly necessary to The ex: haust valve cams l5 are preferably nottwisted. They could, if desired, be given an opposite twist to-theintake so as to retard the exhaust opening. It can be readily seen thatif the cam shaft I4 is moved longitudinally. the cam will strike thehigh point I! of the camsooner or later according to the direction ofthe twist in the cam and the amount of movement of the cam shaft.Therefore, if means are provided for moving this shaf t longitudinallyin accordance with the speed of the engine, we will automatically have achange or advancement in the time of opening of the intake valves.

Inthis invention means are provided for automatically moving the shaftIt as follows: a cam shaft gear 20, constantly in mesh with the drivegear I3, is mounted upon a splined or squared portion 2i of the shaft Iso that it can not rotate thereon but is free to move-longitudinally.The shaft l4 beyond the squared portion 2| is provided with coarsethreads 22 and a cylindrical nut 23 is threaded upon these threads.

The nut 23 is formed with an oppositely extending H-shaped yoke 24 whichis constantly urged and maintained against the face of the gear 20 bymeans of a, compression spring 25. The spring 25 acts against a cap nut26 on the extremity of the shaft ll. At each side of the H-shaped yoke24, a governor weight 21 is hinged'upon a set stud 28. The hinge pointis to one side of the 56 center of gravity of the weight so that thecentrifugal motion of rotation will tend to swing the wei hts outwardly;The shorter extremities of the weights, indicated at 28, then swinginwardly against the sides of the yoke 24, givingit a partial rotation,with reference tothe gear 20. This rotation causes the nut 23 to travelon'the threads I a and pull the cam shaft H outwardly, as indicated bythe broken line position of Fig. 1. v

' As the speed decreases, the weights 21 will swing inwardly causing thenut 23 to travel in the re:- verse direction on the threads so as toreturn the cam shaft to its former position. A pair of springs 8| arecompressed between one leg of each extremity of the yoke 24 and a springlever ll, so that they will tend to return the yoke to its formerposition where it will be stopped by the 7 spring levers ll as shown inFig. 2.

The shaft I4 is prevented from accidental endwise movement by means of apressure spring 32 which acts against a thrust bearing "on the shaftextremity to constantly hold the shaft in its'nor- ,mal at rest"position.

The cam shaft ll carries the usual worm 34 for driving the usualignition timer. It can be readilyseen that this worm will movelongitudinally with the shaft It so that when the valve 1 timing ischanged, or advanced the ignition will also be simultaneously changed oradvanced be cause of the longitudinal shift of the worm 23.

The return swing of the weights 2! and any wear or looseness can beadjusted by means of set screws 35 by means of which the normal or atrest" position of the shaft can be regulated.- The weights 2! arepreferably provided with ears or flaps 3| which overlap the face of theyoke 24 and assist the spring 25 in holding the yoke against comprisinga longitudinally shiftable valve cam shaft; twisted cams on said shafthaving their high points occurring at differing positions throughouttheir length; a driven gear for imparting rotation to said shaft, saidshaft being free to move axially through said gear; threads on saidshaft adjacent said gear; a nut on said threads; means for causing saidnut to rotate with said gear; governor weights rotatingwith said nut andgear;.and means for causing the -centrifugal expansion of said weightsto shift said nut in relation to said gear.

3. Means for advancing the valve timing of an engine in accordance withthe speed thereof comprising: a longitudinally shiftable valve camshaft; twisted cams on said shaft having their high points occurring atdiffering positions throughout their length; a driven gear for impartingrotation to said shaft, said shaft being free to move axially throughsaid gear; \threads on said shaft adjacent said gear; a nut "on saidthreads; arms projecting from said nut over the face of said gear;governor w'eights pivoted on said face of said gear so as to swingoutwardly comprising: a longitudinally shiftable valve cam shaft;twistedcams on said shaft having their high points occurring atdiffering positions throughout their length; a driven gear for impartingrotation to said shaft, said shaft being free to move axially throughsaid gear; threads on said shaft adjacent said gear; a nut on saidthreads; means for causing said nut to rotate with said gear; and meansfor shifting the posi-' tion of said nut with reference to said gearinac'- cordance with the speed of said engine.

2. Means for advancing the valve timing of an engine in accordance with'the speed thereof from centrifugal action when said gear rotates; andprojections on said weights for contacting said arms when said weightsswing outward so as to shift said nut on said threads with reference tosaid gear.

4. Means for advancing the valve timing of an engine in accordance withthe speed thereof comprising: a longitudinally shiftable valve camshaft; twisted cams on'said shaft having their high points occurring atdiffering positions throughout their length; 'a driven gear forimparting rotation to said shaft, said shaft being free to move axiallythrough said gear; threads on said shaft adjacent said gear; a nut onsaid threads; means for causing said nut to rotate with said gear; meansfor shifting the position of said nut with reference to said gear inaccordance with the speed of said engine; and means for preventing saidnut from separating from said gear. I

5. Means for advancing the valve timin of an engine in accordance withthe speed there f comprising: a longitudinally shiftable valve camshaft; twisted cams on said shaft having their high points occurring .atdiffering positions throughout their length; a driven gear for impartingrotation to said shaft, said shaft being free to move axially throughsaid gear; threads on said shaft adjacent said gear; a nut on saidthreads; means for causing said nut to rotate with said gear; governorweights rotating with said nutand gear; means for causing thecentrifugal expansion of said weights to shift said nut in relation tosaid gear; and spring means for returning said weights against saidcentrifugal expansion. i

' EDMOND LA CHAPELLE.

